Stability of capillary–gravity interfacial waves between two bounded fluids

摘要: Two‐dimensional periodic capillary–gravity waves at the interface between two bounded fluids of different densities are considered. Based on a variational formulation, relation wave frequency and amplitude is obtained through weakly nonlinear analysis. All classes space‐periodic studied: traveling standing as well degenerate class mixed waves. As opposed to water waves, interfacial exist even for pure gravity The stability with respect three‐dimensional modulations then studied. By using method multiple scales, Davey–Stewartson‐type equations obtained. A detailed analysis performed in three cases: when one layer infinitely deep, both layers deep. main results oblique (i.e., combined longitudinal transverse) reveal mostly stabilizing effect density ratio destabilizing